Replacing The Mechanical Seal - Wilo Stratos GIGA Einbau- Und Betriebsanleitung

13.4

Replacing the mechanical seal

Installation and operating instructions • Wilo-Stratos GIGA, Wilo-Stratos GIGA B • Ed.01/2023-05
There may be a slight amount of drip leakage during the running-in period. Even during
normal operation of the pump, it is normal for there to be slight leakage with the occasional
formation of drops.
In addition, carry out a visual inspection regularly. If leakage is clearly visible, replace the
gasket.
Wilo offers a repair kit which contains the necessary parts for replacement.
NOTICE
The magnets inside the motor pose no risk to persons with pacemakers,
provided that the motor is not opened and the rotor is not dismantled.
The mechanical seal can be replaced without any risk.
Dismantling:
WARNING
Risk of scalding!
At high fluid temperatures and system pressures, allow the pump to cool
down first and then depressurise the system.
1. Disconnect the system from the power supply and secure it against being switched on
again without authorisation.
2. Make sure it is not live.
3. Earth the work area and short-circuit.
4. Close the shut-off devices upstream and downstream of the pump.
5. Disconnect the mains connection cable. If present, remove the cable for the differen-
tial pressure sensor.
6. Depressurise the pump by opening the air vent valve (Fig. I/II, Item 1.31).
NOTICE
For all subsequent work, observe the torque specified for the respective
thread type (see tightening torques table)!
7. If present, remove the pressure measurement lines of the differential pressure sensor.
8. Disconnect the motor and mains connection cables if the cable is too short for dis-
mantling the drive.
9. Remove the coupling guard (Fig. I/II, Item 1.32) using a suitable tool (e.g. screwdriver).
10. Loosen the coupling screws (Fig. I/II, Item 1.5) on the coupling unit.
11. Loosen the motor fastening screws (Fig. I/II, Item 5) on the motor flange and lift the
drive off the pump using suitable hoisting gear.
12. Remove the lantern unit with coupling, shaft, mechanical seal and impeller from the
pump housing by loosening the lantern fastening screws (Fig. I/II, Item 4).
13. Loosen the impeller fastening nut (Fig. I/II, Item 1.11), remove the conical spring
washer underneath (Fig. I/II, Item 1.12) and pull the impeller (Fig. I/II, Item 1.13) off the
pump shaft.
14. Remove the shim (Fig. I/II, Item 1.16) and, if necessary, the key (Fig. I/II, Item 1.43).
15. Remove the mechanical seal spring (Fig. I/II, Item 1.21) from the shaft.
16. Pull the coupling (Fig. I/II, Item 1.5) with pump shaft from the lantern.
17. Thoroughly clean the sliding/seat surfaces of the shaft. If the shaft is damaged, also
replace the shaft.
18. Remove the stationary ring on the mechanical seal with the collar from the lantern
flange and the O-ring (Fig. I/II, Item 1.14). Clean the gasket seats.
en
145